I'm running build 2217. I use the Nil theme with a slightly customized tmTheme for my own colors.

For months the folders in the sidebar have been an off-white color. Today, I opened ST and found this:

Uh..

Apparently this is the color that folders are supposed to be according to the Nil theme. If I open "Theme - Nil/Nil.sublime-theme", for "class": "sidebar_heading" the color is set to [155, 110, 248], which is indeed what color that text is.

Question is, why did this suddenly happen? I think I installed and uninstalled an unrelated plugin recently, but I didn't notice any color change until today. What's even more confusing is that I can't seem to change it back. Modifying the Nil.sublime-theme file has no effect on the color, and I have no idea where else I would be able to change it.

..is anyone else kinda annoyed at how nightmarishly difficult it is to figure out where some aspect of the editor is getting its configuration? And how unbelievably under-documented all the configuration stuff is?

If it is talk us through some more of what you have done to get to where you are and what you have tried to get to a different place.

When you said you have been running a personally altered version of the Nil theme how did you do that?Did you alter the default Nil theme or did you create a copy of the Nil theme, name it something different (maybe 'myNil.tmTheme')?Where did you put the theme file holding your preferred settings? Which folder path?

I have sympathy for your difficulties in handling all the options ST provides but it is kinda impossible to give the user huge customising power without also giving us the power to get it wrong.

I can't say I agree with your concerns around where to put files to create overrides to behaviour. The rules themselves are fairly simple and I consider them adequately documented. Whenever I get things wrong it is my fault for trying to do something I am not quite clever enough to do or, more importantly, failing to keep adequate notes of my changes and experiments so I can back them out or replicate them. I am not sure about your issues here so I am not painting you with the same brush I paint myself with.

I didn't modify the default Nil theme file. I created a new tmTheme file based on it called "Mine.tmTheme" which lives in the User directory.

In my user settings file, the "color_scheme" key is set to "Packages/User/Mine.tmTheme" and "theme" is set to "Nil.sublime-theme". There is only one Nil.sublime-theme file in my entire packages directory, and it's in Packages/Theme - Nil.

The confusing part is that even if I try to change that Nil.sublime-theme file, nothing changes. I can enter ridiculous values for any aspect of the theme and nothing happens. And it's not like my tmTheme file is overriding it -- as far as I can tell, there's no way to theme the sidebar with tmTheme files. (On the subject: why the hell are there both sublime-theme AND tmTheme files?) So this is why I feel like I'm in configuration hell: it seems like SOME file is overriding the values set in Nil.sublime-theme but I can't for the life of me figure out what file.

I noticed the same issue in my install. The change seemed to happen out of the blue, when I wasn't messing around with any particular settings. I wasn't paying enough attention to note if it happened after installing a particular extension or not, however.

I did figure out how to fix it...the setting you had found isn't quite the right one, however. Look for this section:

Like I said, I can change literally anything in Nil.sublime-theme and it has no effect on the theme. It DOES seem to be being parsed, as if I enter invalid JSON everything goes weird. It's just that for some reason all the values of the theme items have zero effect.